Thermostat



March 8,1955 F. RINGRUBER mL 2,703,832

THERMOSTAT Filed Sept. 19, 1952 l l l 1 1 l l1 Unid SWS Pam@ 2,103,832 i THERMOSTAT Frank Reingruber, Yonkers, and Joseph Reingfruber, Astoria, N. Y.

Application September 19, 1952, Serial No. 310,516 2 Claims. (Cl. Z110- 139) The invention disclosed in this patent application'is a thermostat of the type covered in Patent No. 2,5 84,924` .of February 5, 19.52, in which control for cireuitmaking oi' breaking or other purposes is effected by the conjoint action of members having different coeicients of expansion attached together at their ends, and the member of lower coetticiency being a strip having an intermediate portion arched away from the other member and serving as the element for accomplishing the desired control.

The present invention is concerned with controlling the range of operation of the device.

Special objects of the invention are to provide simple and effective means for accurately Calibrating the range of operation of the thermostat and to provide this in an inexpensive form readily applicable to thermostats of the type indicated.

Other objects of the invention are to improve the construction and operation of the low expansion element and to maintain the same positive and reliable in action.

Other desirable objects and the novel features through which the purposes of the invention are attained are set forth and will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates certain present commercial embodiments of the invention but structural features may be modified and changed, all within the true intent and scope of the invention as hereinafter defined and claimed.

Fig. l in the drawing is a broken part longitudinal sectional view of one of the thermostats;

Fig. 2 is a top plan view of the same;

Fig. 3 is a horizontal sectional view as on substantially the plane of line 33 of Fig. 1;

Fig. 4 is an enlarged transverse sectional detail across i the low expansion spring strip as on substantially the plane of line 4-4 of Fig. 5,

Fig. 5 is a broken longitudinal sectional view as on substantially the plane of line 5 5 of Fig. 4;

Fig. 6 is a broken longitudinal sectional view of a modified form of the invention.

Fig. l shows the member of relatively high expansibility as a flat bar 7 designed to be attached in heat receptive relation to the device to be controlled, such as an electric iron or the like, and the member of lower expansibility, as a liat strip having a raised platform 8 at the center and diversely extending straight leg portions 9 terminating in flat feet or pad portions 10 rigidly secured to the base member.

A shell or casing structure 11 is shown attached t0 the ends of the bar, at 12, and as serving as a carrier for the companion switch springs 13, 14, carrying at their free ends the contacts 15, 16.

The stud 17 having a screw mounting at 18 in the top of the housing, carries an insulating button 19 bearing on the top switch spring 14.

This stud serves as a Calibrating screw for positioning the upper contact spring 14 in respect to the lower spring 13. The flat table or platform 8 at the center of the low expansion thermal strip carries an insulator for forcing the lower contact spring 13 upwardly into circuit closing relation with the upper contact spring 14.

This insulator is shown as a flanged conical button 20 of insulating material, and a special feature is that it is seated in and carried by an externally threaded f 2,703,832 lteefsd Mea 82,1955

ing 25 in thecenter of the platform.

The lower end of the hollow screw stud is shown as cross slotted at 26 for a screw-driver or"othe'r. adjusting implement, and the base plate 7 is shown ,as having an opening 27 opposite the end of thelscrew studfor entry of the screw-driver or other adjusting tool. i

The integral, one-piece form of screw seat is shown in Fig. 6 as a iiange 28 extruded or embossed downwardly out of the platform portion of the thermal spring, internally screw threaded to match the threads of the tubular screw stud 21.

From Fig. l it will be clear that with the aid of a screw-driver or other such implement inserted through opening 27 in the base, the screw stud 21 may be turned one way or the other to cause the insulating button 20 to force the lower spring contact into engagement with the upper spring contact, or to release it from engagement.

Thus adjustments can be quickly made to calibrate the effective range of action of the thermostat.

The invention makes it possible to offset and compensate for variations in fit and size of parts and to cure inaccuracies that might not otherwise be detected or remedied. The tension applied to the switch springs by the thermal spring may be increased or reduced by simple rotary adjustments of the insulator carrying screw stud 21, and adjustments on this same order may be employed to preset and determine the point of engagement and timing of the action of the thermostat.

The applicationn of the screw seat to the platform portion of the thermal spring serves to reinforce and stiften this central portion of the spring, a desirable factor in the construction and operation of the device.

The adjustments ofthe thermal spring insulator 20 are independent of the Calibrating screw 17 adjustments, but the two may be adjusted in a cooperative sense to locate the contact springs in a desired position and to determine the circuit opening and closing conditions. The opposing relation of the two adjustable contact buttons 19 and 20 bearing against opposite sides of the two switch contact springs, enables these springs to be firmly and positively adjusted and tensioned as required.

While terminals for the switch springs have not been illustrated, it will be apparent from the drawing that any suitable wiring tabs or terminals may be applied to the tubular rivets or other fastenings 29, 30, employed for securing the switch springs in the casing.

What is claimed is:

l. A thermostat comprising a bar of relatively high thermal expansibility and a spring strip of relatively low expansibility rigidly connected at opposite ends with said bar and having an intermediate portion spaced away from the bar whereby upon thermal expansion of the bar said spaced intermediate portion of the strip will be drawn toward the bar, a member on said spaced intermediate portion of the strip for eiecting actuation of an element to be controlled, by means for adjusting said member on the strip in respect to said bar for predetermining the operation of said member on the element to be controlled, including a screw stud carrying said member and a at plate secured over said spring strip and having a screw seat for said stud, said spring strip having an opening therethrough, said screw seat being formed in a bushed portion of the llat plate extending through said opening in the spring strip and the edges of the at plate being turned down under the edges of the spring stn'p whereby said screw seat il delinitely located and held against rotation on the spring strip, enabling adjustment of the screw stud to vary the operating range of the thermostat.

, 2. A thermostat having a controllable range of operation and comprising a bar of relatively high thermal expansibility, a spring strip of relatively low expansi- -bility rigidly connected at opposite ends with said bar firmament and having an intermediate portion arched away from the bar so that upon thermal expansion of the bar the arched intermediate portion of the strip will be drawn ,toward the bar, upper and lower Contact springs mounted over said arched intermediate portion of the spring strip, a temperature setting screw bearing on top 0f the upper contact spring and adjustable to determine engagement of said upper contact spring'by the lower contact.spring for temperature, a screw seat carried by the arched intermediate portion of the spring strip, a

screw stud supported in said screw seat and having an v operating head at the lower end disposed toward the bar, an insulating button mounted in the opposite up- 4 per end of said screw stud and engageable with the lower contact spring to hold the same in engagement with the upper contact spring and said bar being open opposite the operating head on the lower end of said screw stud for engagement by an adjusting implement for predetermining the range of operation of the thermostat independently of the temperature adjustment effected by the temperature setting screw.

References Cited in the le of this patent UNITED STATES PATENTS 474,542 Brintnell May l0, 1892 .1,190,205 Storey July 4, 1916 1,380,291 Danylchuk May 3l, 1921 2,197,276 Mulvaney Apr. 16, 1940 2,496,917 Poitras Feb. 7, 1950 2,649,523 Mulvaney et al. Aug. 18, 1953 FOREIGN PATENTS 35.923 Denmark Apr. 15, 1926 

